Abstract: The present invention provides an isolated nucleic acid encoding an approximately 120-128 kilodalton antigen of Helicobacter pylori, or an antigenic fragment thereof, wherein the antigen is associated with peptic ulceration. The present invention also provides methods of detecting the presence of a Helicobacter pylori strain possessing the 120-128 kilodalton antigen in a subject, comprising the steps of contacting an antibody-containing sample from the subject with a detectable amount of the tagA antigen or antigenic polypeptide of the present invention and detecting the binding of the antigen or fragment and the antibody. The detection of a strain expressing the TagA antigen is an indication of predisposition to peptic ulceration and gastric carcinoma. A mutant H. pylori not expressing a functional TagA antigen is also provided.

Abstract: This invention relates to a purified Helicobacter pylori vacuolating toxin and methods to use this toxin to produce protective antibodies against H. pylori infection. Antiserum to this antigen can be used to detect the toxin. Methods to detect anti-toxin antibodies determine the susceptibility of a patient to develop peptic ulcer disease, gastric carcinoma, or other clinical consequences of H. pylori infection.

Abstract: This invention relates to a purified Helicobacter pylori vacuolating toxin and methods to use this toxin to produce protective antibodies against H. pylori infection. Antiserum to this antigen can be used to detect the toxin. Methods to detect anti-toxin antibodies determine the susceptibility of a patient to develop peptic ulcer disease, gastric carcinoma, or other clinical consequences of H. pylori infection.

Abstract: The present invention provides an isolated nucleic acid encoding an approximately 120-128 kilodalton antigen of Helicobacter pylori, or an antigenic fragment thereof, wherein the antigen is associated with peptic ulceration. The present invention also provides methods of detecting the presence of a Helicobacter pylori strain possessing the 120-128 kilodalton antigen in a subject, comprising the steps of contacting an antibody-containing sample from the subject with a detectable amount of the tagA antigen or antigenic polypeptide of the present invention and detecting the binding of the antigen or fragment and the antibody. The detection of a strain expressing the TagA antigen is an indication of predisposition to peptic ulceration and gastric carcinoma. A mutant H. pylori not expressing a functional TagA antigen is also provided.

Abstract: This invention relates to a purified Helicobacter pylori vacuolating toxin and methods to use this toxin to produce protective antibodies against H. pylori infection. Antiserum to this antigen can be used to detect the toxin. Methods to detect anti-toxin antibodies determine the susceptibility of a patient to develop peptic ulcer disease, gastric carcinoma, or other clinical consequences of H. pylori infection.

Abstract: An isolated nucleic acid encoding an approximately 120-128 kilodalton antigen of Helicobacter pylori, or an antigenic fragment thereof, wherein the antigen is associated with peptic ulceration. The present invention also provides methods of detecting the presence of a Helicobacter pylori strain possessing the 120-128 kilodalton antigen in a subject, comprising the steps of contacting an antibody-containing sample from the subject with a detectable amount of the tagA antigen or antigenic polypeptide of the present invention and detecting the binding of the antigen or fragment and the antibody. The detection of a strain expressing the TagA antigen is an indication of predisposition to peptic ulceration and gastric carcinoma. A mutant H. pylori not expressing a functional TagA antigen is also provided.

Abstract: An isolated nucleic acid encoding the Helicobacter pylori vacuolating toxin, consisting of the nucleotides 101 through 3964 of the nucleotide sequence defined in the Sequence Listing as SEQ ID NO:1 is provided. An isolated nucleic acid from Helicobacter pylori comprising the nucleotide sequence defined in the Sequence Listing as SEQ ID NO:3 is provided. Isolated nucleic acids that selectively hybridize with the nucleic acids of the invention are provided. Also provided is a genetically altered mutant strain of H. pylori that does not express a functional vacuolating toxin. Purified proteins encoded by the nucleic acids of the invention are provided. A composition comprising an immunogenic amount of a protein or mutant strain of the invention in a pharmaceutically acceptable carrier is provided. A method of immunizing a subject against infection by H. pylori, comprising administering to the subject an immunogenic composition of the invention is provided.

Abstract: The present invention provides an isolated nucleic acid encoding an approximately 120-128 kilodalton antigen of Helicobacter pylori, or an antigenic fragment thereof, wherein the antigen is associated with peptic ulceration. The present invention also provides methods of detecting the presence of a Helicobacter pylori strain possessing the 120-128 kilodalton antigen in a subject, comprising the steps of contacting an antibody-containing sample from the subject with a detectable amount of the tagA antigen or antigenic fragment of the present invention and detecting the reaction of the antigen or fragment and the antibody. A mutant H. pylori not expressing a functional tagA antigen is also provided.